Quantification of Skeletal Muscle Perfusion in Peripheral Artery Disease Using 18F-Sodium Fluoride Positron Emission Tomography Imaging

BACKGROUND

Perfusion deficits contribute to symptom severity, morbidity, and death in peripheral artery disease (PAD); however, no standard method for quantifying absolute measures of skeletal muscle perfusion exists. This study sought to preclinically test and clinically translate a positron emission tomography (PET) imaging approach using an atherosclerosis-targeted radionuclide, fluorine-18-sodium fluoride (18F-NaF), to quantify absolute perfusion in PAD.

METHODS AND RESULTS

Eight Yorkshire pigs underwent unilateral femoral artery ligation and dynamic 18F-NaF PET/computed tomography imaging on the day of and 2 weeks after occlusion. Following 2-week imaging, calf muscles were harvested to quantify microvascular density. PET methodology was validated with microspheres in 4 additional pig studies and translated to patients with PAD (n=39) to quantify differences in calf perfusion across clinical symptoms/stages and perfusion responses in a case of revascularization. Associations between PET perfusion, ankle-brachial index, toe-brachial index, and toe pressure were assessed in relation to symptoms. 18F-NaF PET/computed tomography quantified significant deficits in calf perfusion in pigs following arterial occlusion and perfusion recovery 2 weeks after occlusion that coincided with increased muscle microvascular density. Additional studies confirmed that PET-derived perfusion measures agreed with microsphere-derived perfusion measures. Translation of imaging methods demonstrated significant decreases in calf perfusion with increasing severity of PAD and quantified perfusion responses to revascularization. Perfusion measures were also significantly associated with symptom severity, whereas traditional hemodynamic measures were not.

CONCLUSIONS

18F-NaF PET imaging quantifies perfusion deficits that correspond to clinical stages of PAD and represents a novel perfusion imaging strategy that could be partnered with atherosclerosis-targeted 18F-NaF PET imaging using a single radioisotope injection.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03622359.

Cold Agglutinin Disease in a Rhesus Macaque (Macaca mulatta)

Cold agglutinin disease (CAD) is a condition involving anemia and its related symptoms; it is caused by autoantibodies that bind and agglutinate red blood cells in areas susceptible to hypothermia, such as extremities exposed to cold temperatures. CAD is rare, with 5 to 20 human cases per million individuals. In this report, we describe a case of CAD in a previously healthy and experimentally naïve adult Indian rhesus macaque that was housed indoors and presented with blood in the urine. After our observations of hemoglobinuria and anemia led us to suspect CAD, we demonstrated that the macaque's blood agglutinated at reduced temperatures. We also noticed that the provision of cold foraging treats triggered episodes of hemoglobinuria. Further investigation revealed that serum from the macaque agglutinated RBCs in vitro with high thermal amplitude (at or below 30 °C) and had an antibody titer of 8 to 32. The serum contained autoantibodies of the immunoglobulin M (IgM) isotype; agglutinins of the IgG isotype were not detected. The cold-dependent IgM autoantibodies in the serum from the affected macaque reacted against a common RBC antigen because RBCs collected from other macaques were bound and agglutinated by the affected animal's IgM under cold conditions. This in vitro binding activity was reversible when the test temperature was returned to normal body temperature (37 °C). These findings demonstrated cold-dependent RBC-specific IgM agglutinins and led us to a diagnosis of CAD. This is the first documented case of spontaneous CAD in a rhesus macaque.

Cold Agglutinin Disease in a Rhesus Macaque (Macaca mulatta)

Cold agglutinin disease (CAD) is a condition involving anemia and its related symptoms; it is caused by autoantibodiesthat bind and agglutinate red blood cells in areas susceptible to hypothermia, such as extremities exposed to cold temperatures.CAD is rare, with 5 to 20 human cases per million individuals. In this report, we describe a case of CAD in a previouslyhealthy and experimentally naïve adult Indian rhesus macaque that was housed indoors and presented with blood in theurine. After our observations of hemoglobinuria and anemia led us to suspect CAD, we demonstrated that the macaque'sblood agglutinated at reduced temperatures. We also noticed that the provision of cold foraging treats triggered episodes ofhemoglobinuria. Further investigation revealed that serum from the macaque agglutinated RBCs in vitro with high thermalamplitude (at or below 30 °C) and had an antibody titer of 8 to 32. The serum contained autoantibodies of the immunoglobulinM (IgM) isotype; agglutinins of the IgG isotype were not detected. The cold-dependent IgM autoantibodies in the serum fromthe affected macaque reacted against a common RBC antigen because RBCs collected from other macaques were bound andagglutinated by the affected animal's IgM under cold conditions. This in vitro binding activity was reversible when the testtemperature was returned to normal body temperature (37 °C). These findings demonstrated cold-dependent RBC-specific IgMagglutinins and led us to a diagnosis of CAD. This is the first documented case of spontaneous CAD in a rhesus macaque.

Physiotherapy for primary frozen shoulder in secondary care: Developing and implementing stand-alone and post operative protocols for UK FROST and inferences for wider practice

OBJECTIVES

The United Kingdom Frozen Shoulder Trial (UK FROST) compares stand-alone physiotherapy and two operative procedures, both with post operative rehabilitation, for primary frozen shoulder in secondary care. We developed physiotherapy protocols for UK FROST, incorporating best evidence but recognizing uncertainty and allowing flexibility.

METHODS

We screened a UK Department of Health systematic review and UK evidence-based guidelines (Hanchard et al., 2012; Maund et al., 2012) for recommendations, and previous surveys of UK physiotherapists (Hanchard et al., 2011, 2013) for strong consensus. We conducted a two-stage, questionnaire-based, modified Delphi survey of shoulder specialist physiotherapists in the UK National Health Service. This required positive, negative or neutral ratings of possible interventions in four clinical contexts (stand-alone physiotherapy for, respectively, predominantly painful and predominantly stiff frozen shoulder; and post operative physiotherapy for, respectively, predominantly painful and predominantly stiff frozen shoulder). We proposed respectively mandating or recommending interventions with 100% and 90% positive consensus, and respectively disallowing or discouraging interventions with 90% and 80% negative consensus. Other interventions would be optional.

RESULTS

The systematic review and guideline recommended including steroid injection and manual mobilizations in non-operative care, and we mandated these for stand-alone physiotherapy. Consensus in the pre-existing surveys strongly favoured advice, education and home exercises, which we mandated across contexts. The Delphi survey led to recommendation of some supervised exercise modalities, plus the disallowing or discouragement-in various contexts-of immobilization and some 'higher-tech' electrotherapies and alternative therapies.

CONCLUSIONS

We developed physiotherapy protocols despite incomplete empirical evidence. Their clear structure enabled implementation in data-sheets designed to facilitate recording, monitoring of fidelity and reporting of interventions. Other trials involving physiotherapy may benefit from this approach.

Developing, delivering and documenting rehabilitation in a multi-centre randomised controlled surgical trial: experiences from the ProFHER trial

Objectives

A rigorous approach to developing, delivering and documenting rehabilitation within randomised controlled trials of surgical interventions is required to underpin the generation of reliable and usable evidence. This article describes the key processes used to ensure provision of good quality and comparable rehabilitation to all participants of a multi-centre randomised controlled trial comparing surgery with conservative treatment of proximal humeral fractures in adults.

Methods

These processes included the development of a patient information leaflet on self-care during sling immobilisation, the development of a basic treatment physiotherapy protocol that received input and endorsement by specialist physiotherapists providing patient care, and establishing an expectation for the provision of home exercises. Specially designed forms were also developed to facilitate reliable reporting of the physiotherapy care that patients received.

Results

All three initiatives were successfully implemented, alongside the measures to optimise the documentation of physiotherapy. Thus, all participating sites that recruited patients provided the sling immobilisation leaflet, all adhered to the physiotherapy protocol and all provided home exercises. There was exemplary completion of the physiotherapy forms that often reflected a complex patient care pathway. These data demonstrated equal and high access to and implementation of physiotherapy between groups, including the performance of home exercises.

Conclusion

In order to increase the validity and relevance of the evidence from trials of surgical interventions and meet international reporting standards, careful attention to study design, conduct and reporting of the intrinsic rehabilitation components is required. The involvement of rehabilitation specialists is crucial to achieving this.

Cite this article: Bone Joint Res 2014;3:335–40.

Feasibility and safety of systemic rAAV9-hNAGLU delivery for treating mucopolysaccharidosis IIIB: toxicology, biodistribution, and immunological assessments in primates

No treatment is currently available for mucopolysaccharidosis (MPS) IIIB, a neuropathic lysosomal storage disease caused by autosomal recessive defect in α-N-acetylglucosaminidase (NAGLU). In anticipation of a clinical gene therapy treatment for MPS IIIB in humans, we tested the rAAV9-CMV-hNAGLU vector administration to cynomolgus monkeys (n=8) at 1E13 vg/kg or 2E13 vg/kg via intravenous injection. No adverse events or detectable toxicity occurred over a 6-month period. Gene delivery resulted in persistent global central nervous system and broad somatic transduction, with NAGLU activity detected at 2.9-12-fold above endogenous levels in somatic tissues and 1.3-3-fold above endogenous levels in the brain. Secreted rNAGLU was detected in serum. Low levels of preexisting anti-AAV9 antibodies (Abs) did not diminish vector transduction. Importantly, high-level preexisting anti-AAV9 Abs lead to reduced transduction in liver and other somatic tissues, but had no detectable impact on transgene expression in the brain. Enzyme-linked immunoabsorbent assay showed Ab responses to both AAV9 and rNAGLU in treated animals. Serum anti-hNAGLU Abs, but not anti-AAV9 Abs, correlated with the loss of circulating rNAGLU enzyme. However, serum Abs did not affect tissue rNAGLU activity levels. Weekly or monthly peripheral blood interferon-γ enzyme-linked immunospot assays detected a CD4(+) T-cell (Th-1) response to rNAGLU only at 4 weeks postinjection in one treated subject, without observable correlation to tissue transduction levels. The treatment did not result in detectable CTL responses to either AAV9 or rNAGLU. Our data demonstrate an effective and safe profile for systemic rAAV9-hNAGLU vector delivery in nonhuman primates, supporting its clinical potential in humans.

CD4+ helper T cells and immunity to therapeutic proteins in gene therapy (P4431)

Adeno-associated (AAV) vectors are being assessed for gene replacement therapy in humans. Proteins encoded by the vector transgene are potentially foreign. Strategies to temper destructive immune responses may be required to achieve a therapeutic effect, particularly in diseases like Duchenne Muscular Dystrophy where the defective gene to be replaced has a large frame-shifting deletion. Here we studied the impact of immunity on expression of enhanced green fluorescent protein (eGFP) in AAV-transduced skeletal muscle of rhesus macaques. Antibodies to eGFP developed rapidly after AAV vector delivery to the tibialis anterior muscle. Cellular immunity was variable. In some animals, strong CD4+ helper and CD8+ cytotoxic T cells were detected in blood 2 weeks after vector administration. In others, low frequency responses were not detected until week 5-6. Regardless of the pace of the response, eGFP was cleared or substantially diminished in muscle after week 6. Antibody-mediated depletion of CD4+ T cells before AAV vector treatment delayed antibody and CD8+ T cell immunity and facilitated robust expression of eGFP persisted through day 42. Some positive muscle fibers were still visible at month 10, an unexpected finding that suggested an inability to sustain destructive cellular immune responses initially primed without CD4+ T cell help. The capacity for recall of eGFP-CD8+ T cell responses upon administration of a serologically distinct AAV vector is now being assessed.

Management of frozen shoulder: a systematic review and cost-effectiveness analysis

BACKGROUND

Frozen shoulder is condition in which movement of the shoulder becomes restricted. It can be described as either primary (idiopathic) whereby the aetiology is unknown, or secondary, when it can be attributed to another cause. It is commonly a self-limiting condition, of approximately 1 to 3 years' duration, though incomplete resolution can occur.

OBJECTIVES

To evaluate the clinical effectiveness and cost-effectiveness of treatments for primary frozen shoulder, identify the most appropriate intervention by stage of condition and highlight any gaps in the evidence.

DATA SOURCES

A systematic review was conducted. Nineteen databases and other sources including the Cumulative Index to Nursing and Allied Health (CINAHL), Science Citation Index, BIOSIS Previews and Database of Abstracts of Reviews of Effects (DARE) were searched up to March 2010 and EMBASE and MEDLINE up to January 2011, without language restrictions. MEDLINE, CINAHL and PsycINFO were searched in June 2010 for studies of patients' views about treatment.

REVIEW METHODS

Randomised controlled trials (RCTs) evaluating physical therapies, arthrographic distension, steroid injection, sodium hyaluronate injection, manipulation under anaesthesia, capsular release or watchful waiting, alone or in combination were eligible for inclusion. Patients with primary frozen shoulder (with or without diabetes) were included. Quasi-experimental studies were included in the absence of RCTs and case series for manipulation under anaesthesia (MUA) and capsular release only. Full economic evaluations meeting the intervention and population inclusion criteria of the clinical review were included. Two researchers independently screened studies for relevance based on the inclusion criteria. One reviewer extracted data and assessed study quality; this was checked by a second reviewer. The main outcomes of interest were pain, range of movement, function and disability, quality of life and adverse events. The analysis comprised a narrative synthesis and pair-wise meta-analysis. A mixed-treatment comparison (MTC) was also undertaken. An economic decision model was intended, but was found to be implausible because of a lack of available evidence. Resource use was estimated from clinical advisors and combined with quality-adjusted life-years obtained through mapping to present tentative cost-effectiveness results.

RESULTS

Thirty-one clinical effectiveness studies and one economic evaluation were included. The clinical effectiveness studies evaluated steroid injection, sodium hyaluronate, supervised neglect, physical therapy (mainly physiotherapy), acupuncture, MUA, distension and capsular release. Many of the studies identified were at high risk of bias. Because of variation in the interventions and comparators few studies could be pooled in a meta-analysis. Based on single RCTs, and for some outcomes only, short-wave diathermy may be more effective than home exercise. High-grade mobilisation may be more effective than low-grade mobilisation in a population in which most patients have already had treatment. Data from two RCTs showed that there may be benefit from adding a single intra-articular steroid injection to home exercise in patients with frozen shoulder of < 6 months' duration. The same two trials showed that there may be benefit from adding physiotherapy (including mobilisation) to a single steroid injection. Based on a network of nine studies the MTC found that steroid combined with physiotherapy was the only treatment showing a statistically and clinically significant beneficial treatment effect compared with placebo for short-term pain (standardised mean difference -1.58, 95% credible interval -2.96 to -0.42). This analysis was based on only a subset of the evidence, which may explain why the findings are only partly supportive of the main analysis. No studies of patients' views about the treatments were identified. Average costs ranged from £36.16 for unguided steroid injections to £2204 for capsular release. The findings of the mapping suggest a positive relationship between outcome and European Quality of Life-5 Dimensions (EQ-5D) score: a decreasing visual analogue scale score (less pain) was accompanied by an increasing (better) EQ-5D score. The one published economic evaluation suggested that low-grade mobilisation may be more cost-effective than high-grade mobilisation. Our tentative cost-effectiveness analysis suggested that steroid alone may be more cost-effective than steroid plus physiotherapy or physiotherapy alone. These results are very uncertain.

LIMITATIONS

The key limitation was the lack of data available. It was not possible to undertake the planned synthesis exploring the influence of stage of frozen shoulder or the presence of diabetes on treatment effect. As a result of study diversity and poor reporting of outcome data there were few instances where the planned quantitative synthesis was possible or appropriate. Most of the included studies had a small number of participants and may have been underpowered. The lack of available data made the development of a decision-analytic model implausible. We found little evidence on treatment related to stage of condition, treatment pathways, the impact on quality of life, associated resource use and no information on utilities. Without making a number of questionable assumptions modelling was not possible.

CONCLUSIONS

There was limited clinical evidence on the effectiveness of treatments for primary frozen shoulder. The economic evidence was so limited that no conclusions can be made about the cost-effectiveness of the different treatments. High-quality primary research is required.

Large and massive tears of the rotator cuff

The aim of this study was to determine the functional outcome and rate of re-tears following mini-open repair of symptomatic large and massive tears of the rotator cuff using a two-row technique.

The 24 patients included in the study were assessed prospectively before and at a mean of 27 months (18 to 53) after surgery using the Constant and the Oxford Shoulder scores. Ultrasound examination was carried out at follow-up to determine the integrity of the repair. Patient satisfaction was assessed using a simple questionnaire.

The mean Constant score improved significantly from 36 before to 68 after operation (p < 0.0001) and the mean Oxford Shoulder score from 39 to 20 (p < 0.0001). Four of the 24 patients (17%) had a re-tear diagnosed by ultrasound. A total of 21 patients (87.5%) were satisfied with the outcome of their surgery. The repair remained intact in 20 patients (83%). However, the small number of re-tears (four patients) in the study did not allow sufficient analysis to show a difference in outcome in relation to the integrity of the repair.

Conservative management following closed reduction of traumatic anterior dislocation of the shoulder

BACKGROUND

Acute anterior dislocation is the commonest type of shoulder dislocation and usually results from an injury. Subsequently, the shoulder is less stable and more susceptible to redislocation, especially in active young adults.

OBJECTIVES

To compare methods of conservative (non-surgical) management versus no treatment or different methods of conservative management after closed reduction of traumatic anterior dislocation of the shoulder. Interventions include methods of postreduction immobilisation and rehabilitation.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (March 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2005), MEDLINE, EMBASE, the National Research Register (UK), conference proceedings and reference lists of articles.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing various conservative interventions versus control (no or sham treatment) or other conservative interventions applied after closed reduction of traumatic anterior dislocation of the shoulder.

DATA COLLECTION AND ANALYSIS

All authors selected trials, assessed methodological quality and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

One flawed quasi-randomised trial was included. A "preliminary report" gave the results for 40 adults with primary traumatic anterior dislocation of the shoulder treated by post-reduction immobilisation with the arm in either external or internal rotation. There was no statistically significant difference between the two groups in the failure to return to pre-injury sports by previously active athletes, in redislocation or shoulder instability. Similar numbers of participants of the two groups removed their immobiliser before one week had passed.

AUTHORS' CONCLUSIONS

There is a lack of evidence from randomised controlled trials to inform the choices for conservative management following closed reduction of traumatic anterior dislocation of the shoulder. Sufficiently powered, good quality, well reported randomised controlled trials with long-term surveillance of conservative management are required. In particular, trials examining the type and duration of immobilisation would be useful.

Mechanisms of gastro-oesophageal reflux in preterm and term infants with reflux disease

BACKGROUND

Transient lower oesophageal sphincter relaxation (TLOSR) is the predominant mechanism of gastro-oesophageal reflux (GOR) in healthy infants but the mechanisms of GOR in infants with GOR disease (GORD) are poorly understood.

AIMS

To measure the occurrence of TLOSR, GOR, and gastric emptying (GE) rate in preterm and term infants with GORD.

PATIENTS

Thirty six infants were studied and grouped as normals or GORD based on a routine clinical assessment and confirmation of an assessment of GORD by reflux symptom charts and oesophageal pH monitoring.

METHODS

A micromanometric assembly incorporating a micro pH electrode recorded oesophageal motility and pH. GE rate was determined using the (13)C-octanoic acid breath test.

RESULTS

TLOSR was the predominant mechanism of GOR, triggering 50-100% of GOR episodes (median 91.5%). Abdominothoracic straining significantly increased the occurrence of GOR in association with TLOSR. In infants with GORD, the number of TLOSRs overall was similar to normals but the proportion of TLOSRs accompanied by acid GOR was significantly higher than in normals (16.5% v 5.7%, respectively; p<0.001). Infants with GORD had a similar GE rate to normals.

CONCLUSIONS

In infant GORD, acid reflux associated TLOSRs are abnormally common and likely to be a major contributing factor to the pathophysiology of GORD. Infants with GORD do not have delayed GE.

Effect of cisapride on gastric emptying in premature infants with feed intolerance

OBJECTIVE

To assess the effect of cisapride on gastric emptying and gastro-oesophageal reflux (GOR) symptoms in preterm infants with feed intolerance.

METHODS

Sixteen preterm infants (gestational age 24-35 weeks) with feed intolerance were enrolled in the study. Infants were randomized to receive 7 days of cisapride 0.2 mg/kg four times a day, immediately followed by 7 days of placebo or vice versa. Gastric emptying was measured using the [13C]-octanoic acid breath test prior to study entry and repeated on day 5, 6 or 7 after randomization and 5, 6 or 7 days after crossover. The symptoms of GOR were monitored during the study period using a standardized reflux chart. Weight was recorded daily.

RESULTS

There was no change in gastric emptying in infants prescribed cisapride (gastric half-emptying time (t1/2) 31.9 +/- 4.7 vs 34.2 +/- 3.9 min for placebo vs cisapride, respectively; P = 0.65). Infants on cisapride had slower growth and there was no change in reflux symptoms.

CONCLUSIONS

The use of cisapride in preterm infants with feed intolerance cannot be recommended.